The Tissue Culture Core Laboratory will be responsible for providing investigators with cultured cells, antibodies, and facilities for routine microscopic analysis of biological samples. The core will be directed by Dr. Goldstein. He will be assisted by Drs. Y.K. Ho, Richard Anderson, Joachim Herz, and Rob Rawson. The technical work in the Tissue Culture Facility of this Core is carried out by four experienced technicians (Lisa Beatty, Angela Carroll, Jill Fairless, Marissa Hodgin) and one laboratory assistant (Rose Marshall). The Tissue Culture Facility of this Core is located in the Department of Molecular Genetics and consists of three suites of rooms that are used solely for tissue culture. One suite contains four work modules that open into a common work area;the second suite contains three work modules that open into a common work area;and the third suite contains two work modules, one for adenovirus work and the other for baculovirus. Each module is equipped with a sterile work area (Biological Safety Cabinet hood), one or more CO2 incubators, a refrigerator, and an inverted microscope. The common work area in each of the suites contains one or two sterile work areas. The entire facility contains a total of 12 inverted microscopes (6 of which are phase-contrast microscopes), 1 stereo microscope, 15 sterile work areas (hoods), 28 singlechamber CO2 incubators, 2 non-CO2 refrigerated incubators, 1 roller bottle incubator, 3 refrigerated incubator shakers, 3 table-top refrigerated centrifuges, and 9 refrigerators. Four liquid nitrogen freezers for storage of cell lines are located in the common work area adjacent to the work modules. In addition to this standard equipment, we have a Zeiss Axiovert 35 M inverted fluorescence microscope that allows us to visualize cells directly in the Petri dish (under sterile conditions) so as to determine whether or not they have taken up reconstituted fluorescent LDL. This method is the assay of choice for identifying and monitoring mutant cholesterol auxotrophic cell clones that are resistant to amphotericin and thus fail to take up fluorescent LDL (Research Project 1).